A Possible Cause of Decreased Vision in Cryptococcal Meningitis

¹ Clinical Branch, National Eye Institute, National Institutes of Health, Department of Health, Education, and Welfare, Bethesda

The optic nerves, chiasm, optic tracts, and lateral geniculate nuclei of six patients having fatal cryptococcal meningitis were examined histopathologically using the Smith-Quigley stain for myelin and periodic acid-Shiff stain for crytococcal organisms. A correlation was made between the invasion of visual pathways by the cryptococcal organism, the presence or absence of papilledema, and the preservation or loss of visual acuity. In three patients with papilledema and loss of visual acuity, multiple cryptococcal abscesses were present in the optic nerves and tracts. In three patients with papilledema but normal visual acuity, minimal or no involvement of the visual pathways by cryptococcus was noted despite widespread evidence elsewhere in the brain and meninges. It appears that loss of visual acuity in cryptococcal meningitis may represent direct invasion of the visual pathways by the organism.

Key Words: cryptococcal meningitis • visual acuity • increased intracranial pressure.

Submitted on May 23, 1974